VULNERABILITY INTELLIGENCE

CVE-2026-59922

CVSS score7.5 HIGH
EPSS probability0.64%
CISA KEVNot currently listed
Published2026-07-08
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

Weakness classification

  • security-advisories@github.com: CWE-407
  • nvd@nist.gov: CWE-407

Primary references